ACK Asset Management
ACK Asset Management reported 21 stocks worth $856M in its 13F filing for Q2 2026, filed Aug 13, 2026. Its largest holdings are WMS (7.2%), HLIO (7.1%) and LFUS (6.7%). Compared with Q1 2026, the fund opened new positions in GTX, BWA and DNOW, added to CNM, EXP and SWIM, trimmed HLIO, LFUS and ATS and sold out of ROG, NOVT and DXPE.
Holdings
| # | Stock | Value | Weight | Shares | Change | Shares, 8 qtrs | Held |
|---|---|---|---|---|---|---|---|
| 1 |  WMS Advanced Drain Sys Inc Del | $61.2M | 7.2% | 390K | No change | 5 of 8 | |
| 2 |  HLIO Helios Technologies Inc | $60.8M | 7.1% | 681K | −99K (−13%) | 4 of 8 | |
| 3 |  LFUS Littelfuse Inc | $56.9M | 6.7% | 125K | −10K (−7%) | 2 of 8 | |
| 4 |  JHX James Hardie Inds PLC | $55M | 6.4% | 2.1M | No change | 4 of 8 | |
| 5 |  GTX Garrett Motion Inc | $54.3M | 6.3% | 1.5M | New position | 1 of 8 | |
| 6 |  CNM CORE & MAIN INC | $52.6M | 6.1% | 1.1M | +190K (+21%) | 4 of 8 | |
| 7 |  EXP Eagle Matls Inc | $49.5M | 5.8% | 220K | +55K (+33%) | 4 of 8 | |
| 8 |  ATS Ats Corporation | $43.2M | 5.0% | 1.5M | −346K (−19%) | 8 of 8 | |
| 9 |  ASTE Astec Inds Inc | $42.2M | 4.9% | 690K | −96K (−12%) | 4 of 8 | |
| 10 |  MTRN Materion Corp | $40.1M | 4.7% | 135K | −340K (−72%) | 8 of 8 |
Positions at Jun 30, 2026, as reported. Change is against the fund's Q1 2026 filing; weight is the share of the fund's reported stocks.
Sold out
held in Q1 2026, gone in Q2 2026| Stock | Value last quarter | Shares sold |
|---|---|---|
 ROG Rogers Corp | $51M | 475K |
 NOVT Novanta Inc | $44.3M | 375K |
 DXPE Dxp Enterprises Inc | $36.3M | 260K |
 CDNL Cardinal Infrastructure Grou | $34.7M | 874K |
 GVA Granite Constr Inc | $30M | 250K |
🔒 Free account: see all 6.
Reported value
last 8 quartersThe value of the US stocks the fund reported, at quarter end prices. It moves with the market as well as with buying and selling.
Filings for Q2 2026
straight from the SEC| Filed | Form | Quarter | |
|---|---|---|---|
| Aug 13, 2026 | 13F-HR | Q2 2026 | SEC filing ↗ |
Other superinvestors
All hedge fund holdings →ACK Asset Management 13F FAQ
What does ACK Asset Management own?
ACK Asset Management reported 21 stocks worth $856M in its 13F filing for Q2 2026, filed Aug 13, 2026. Its largest holdings are WMS (7.2%), HLIO (7.1%) and LFUS (6.7%). The table above lists every position in the filing (the top 10 without an account).
What did ACK Asset Management buy and sell in Q2 2026?
Compared with Q1 2026: 7 new positions, 5 added to, 5 trimmed and 6 sold out. New positions include GTX, BWA and DNOW. It sold all of ROG, NOVT and DXPE.
When will ACK Asset Management file its next 13F?
Holdings as of Sep 30, 2026 are due by Nov 16, 2026. The filing appears on this page within minutes of reaching the SEC.
How much is ACK Asset Management's portfolio worth?
The Q2 2026 filing reports $856M in US stocks. That leaves out cash, bonds, short positions and most foreign holdings, so the fund's total assets are usually larger.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Holdings come from the fund's SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. The fund may have changed its positions since. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.